Side length versus isometric spacing
On this page the number you set is the length of each triangle side. The height of an equilateral triangle is (√3 / 2) × side. An 8 mm side has a height of about 6.93 mm. Isometric paper on this site instead treats spacing as the perpendicular distance between parallel lines in one family. Use this page when you want to count sides; use isometric graph paper when you want drafting spacing.